Centrifugal separator



March 31, 1942. w. HQ BATH CENTRIFUGAL SEPARATOR Filed Nov. 19, 1940PICri lllllllllffllllfl!!! &

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ATTORNEY Patented Mar. 31, 1942 CENTRIFUGAL SEPABATOR Wilmer HiestandBath, West Conshohocken, Pa

assignor to The Sharples Corporation, Philadelphia, Pa., a corporationof Delaware Application November 19, 1940, Serial No. 366,217

6 Claims.

The present invention pertains to the art of centrifugal separators ofthe type adapted to separate a solid from a liquid or liquids from eachother in a centrifugal rotor during continuous feed to that rotor of amixture to be subjected to the centrifugal separating operation.

In particular, the invention pertains to the provision ofvmeans forsealing the rotor against entry or escape of gases or vapors during theseparating operation, and for automatically permitting drainage ofliquid away from the machine when the operation of the rotor is stopped.

In my prior patent, 1,750,154, I have illustrated a drag mechanism andbearing arrangement for the lower end-of a centrifugal separator of thetubular type, the liquid to be treated being fed into the centrifugalrotor through registering openings in the bottom of the centrifugalframe and the bottom of the centrifugal rotor. Liquid leakage does notoccur from the bottom of this centrifugal rotor during the normal feedof liquid to the rotor and rotation of the rotor. In case someobstruction occurs in the rotor, however, and in any case at thetermination of the rotation of the rotor in the treatment of liquid,liquid drains from the main body of the centrifugal rotor through thedischarge outlet 50 illustrated in Figure 1 of the patent drawing.

While the provision of a constantly open drainage outlet in the lowerpart of the frame constitutes a satisfactory arrangement for permittingdrainage in treatment of many substances, there are certain substanceswhich cannot be satisfactorily treated in a machine provided with suchan open drainage feature. -In the treatment of certain substances, suchas lacquers for example,

the admission of air into the centrifugal rotor is undesirable becauseof changes which may be effected by contact of the air with the liquidunder treatment. When a drainage-outlet such as that illustrated in myprior patent is provided, air is sucked into the centrifugal rotorthrough the drainage space during the normal operation of the machine onthe liquid under treatment, and it is desirable in many cases to preventthis from occurring. In the treatment of certain substances, it is alsofrequently undesirable that vapors of the material under treatment bepermitted to escape to the outside atmosphere, and it is frequentlydesirable for this reason that no opening be provided which communicatesthrough the base of the centrifugal frame directly with the outsideatmosphere.

One method of solving the difficulties encountered in treatment ofliquids presenting problems of the type discussed above has been toprovide a discharge conduit .in place of the outlet 80 of my priorpatent, and to provide a valve in this discharge conduit which preventsescape of vapor or ingress of air, except at times at which the operatormay deliberatelyopen the valve for the purpose of allowing liquid todischarge from the centrifugal rotor and frame.

This expedient has constituted onlya partial solution of the difficulty,however.- In the first place, in case some obstruction occurs in thecentrifugal rotor which causes unexpected leakage of liquid through thebase of the rotor, the provision of a manually operated valve does notconstitute a solution of the problem, since the operator does not knowvwhen to expect this kind of difficulty, and cannot therefore makeprovision for it by operation of the valve at the appropriate time.

As a. consequence of this fact, leakage into the main body of thecentrifugal frame may occur, with a consequent possibility of damage tothe parts of the drag mechanism, in spite of provision of a manuallyoperated valve. A second objection to .the provision of a manuallyoperated valve lies in the fact that the operator may foropened upondrainage of liquid from the centrifugal rotor to permit the drainageliquid to escape from the machine. 7

A further object of the invention has been to control the operation ofthe centrifugal, so as to stop the centrifugal rotor, cut oil feed ofliquid to the centrifugal, or otherwise interrupt the normal operationof the machine in case leakage occurs from the bottom of the centrifugalrotor.

Further objects and advantages of the inven- -tion and the manner inwhich they have been Figure 3 is a detailed side elevation of theautomatic valve of the present invention, showing this valve in openposition.

Referring to the drawing by reference characters, the rotor it of thecentrifugal machine may be of the conventional tubular designillustrated in my prior Patent 1,750,154. This rotor is mounted in acentrifugal frame I l and is driven by suitable pulley and spindle orother driving connections secured to the upper end of the rotor, as willbe evident from inspection of Figure 1 of the drawing of my prior patentreferred to above.

Liquid is fed to the centrifugal rotor through a feed conduit l2 securedto a plug I3 in the lower end of the centrifugal frame II. A nozzle Itis secured centrally within the plug l3 and is aligned with the upperend of the feed conduit l2 in order that liquid fed through the conduitl2 may be injected through the upper end of the nozzle it into thehollow interior of the boss l5 secured to the lower end of the rotor.The boss IE is secured centrally within a dragiflexible bearingmounting) mechanism It of the same general type as that covered by myPatent 1,750,- 154, referred to above.

The hollow interior It of the plug I3 is connected, at its lower end, toa discharge tube ll which may be removably secured within a lateralopening in the plug I'd-by means of a pin and slot connection 22. Thehollow interior of the plug it forms, together with the discharge tubeii, a conduit for directing the flow of liquid away from the lower endof the boss IE on the bottom of the rotor, upon drainage of liquid fromthe rotor.

A disc or valve i9 is removably secured to the lower end of thedischarge tube ii. The disc or valve it is adapted to be retained inclosed position during the feed of liquid to the rotor lb and therotation of that rotor, but is adapted to be automatically opened uponstopping of the rotation of the rotor and drainage of the liquid intothe tube ii. In order to accomplish closure of the connection betweenthe upper side of the disc or valve l9 and the under side of thedischarge tube ll. the disc or valve I9 is pivotally secured to a fixedpart of the apparatus, such as the exterior of the discharge tube W, asillustrated by the pivotal connection 20 of the drawing. The arm itwhich carries the disc or valve 19 and is pivoted at 26 carries acounter-weight 2! which is adapted normally to urge the disc or valve i9with a relatively light force against the under side of the dischargetube IT.

The apparatus consisting of the disc or valve iii, the arm 23, and thecounter-weight 2i is operatively connected to the motor which drives thepump for feeding liquid to the machine to be treated, to the motor whichdrives the centrifugal rotor, or to both of these motors, in such a wayas to interrupt the feed of'liquid to the machine and/or to interruptthe rotation of the centrifugal rotor, upon opening of the valve l9during the normal operation of the machine. This may be accomplished byproviding a switch 26 carried tained in that operation will now beapparent. In the normal operation of the machine, the fluid mixture tobe subjected to centrifugatlon is passed through conduit l2 and nozzlel4 i--to the lower end of the centrifugal rotor Ill, and the centrifugedliquid from within the rotor II] is continuously discharged from asuitable weir or weirs during the continuous rotation of the rotor.

During this normal operation of the machine, the disc or valve I9 ismaintained in sealing relationship against its seat on the lower end ofthe discharge tube ll, the natural suction effect caused by discharge ofliquid from the nozzle l4 into the boss l5 of the centrifugal rotorserving to reinforce the effect of the counter-weight 2| and maintainthe disc or valve I9 in fairly firm sealing relationship against thetube ll.

When the operator desires to discontinue the operation ofcentrifugation, he cuts off the feed of liquid through the conduit l2and stops the rotor Ill. Upon stopping of the rotation of the rotor ill,the liquid still remaining in that rotor will flow downwardly throughthe interior of the boss it into the chamber iii in the interior of theplug l3, and from the chamber l8 into the discharge tube i1. At thistime, the suction effect tending to pull the disc or valve l9 upwardlyhas been discontinued by discontinuance of feed of liquid through thenozzle l4, and the disc or valve is accordingly held in closing positiononly by the force exerted by the counter-weight 2i. As soon as liquidhas drained through the tube ill to a sumcient extent to form asubstantial layer of liquid in the lower end of the tube l'l above thedisc or valve i9, the weight of this liquid will overcome the closingforce exerted by the counter-weight 2i and force the disc or valve it tomove to open position, as illustrated in Figure 3 of the drawing. Thispermits drainage of the liquid from the tube l'l. After drainage ofliquid from the tube ll has been completed, the disc or valve i9 willagain be swung to the closing position illustrated in Figure 2 of thedrawing by the effect of the counter-weight 2i, and the normal operationof the machine may then be resumed.

If, during the normal operation of the machine, some accident occurs,such as an obstruction in passage of liquid through the centrifugalrotor, with the result that liquid is discharged downwardly from therotor into the chamber iii, the apparatus of the invention will functionautomatically in much the same manner as that described above withrespect to the operation occurring when the rotor is stopped. Thus, if asubstantial quantity of liquid leaks into the space it during the normalfeed of liquid to the rotor and rotation of liquid in the rotor, thisliquid will pass downwardly through discharge tube I? and accumulateabove the disc or valve I9. After accumulation of liquid above the discIE! to a predetermined depth, this disc will be forced into openposition against the effect of the counterweght 2!, as illustratedinFigure 3 of the drawing. At the same time, the electrical connectioncontrolled by the switch 24 in the circuit 25 will be broken, with theresult that the feed of liquid to the centrifugal will be stopped, andthe rotation of the centrifugalrotor also stops, if desired. It will beseen that the invention thus provides an arrangement by which the normaloperation of the machine will be automatically stopped in case somethinggoes wrong with the functioning of the machine to effect discharge ofliquid through the normal outlets for the liquid.

Modifications will be obvious to those skilled in the art, and I do nottherefore wish to be limited except by the scope of the followingclaims.

I claim:

1. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to said rotor during rotation thereof, aframe surrounding the bottom portion of said rotor and provided with adischarge outlet for liquid drained from the rotor, a valve associatedwith said outlet and controlling discharge of liquid therefrom, meansassociated with said valve for holding it normally in closed positionduring discharge of liquid until said liquid reaches a predetermineddepth above said valve, and means responsive to accumulation of apredetermined quantity of liquid above said valve for actuating saidvalve to open position.

2. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to the bottom of said rotor duringrotation thereof, a frame surrounding the bottom portion of said rotorand provided with a discharge outlet for liquid drained from the rotor,

a 'valve associated with said outlet and controlling discharge ofliquidtherefrom, means associated with said valve for holding itnormally in closed position during discharge of liquid until said liquidreaches a predetermined depth above said valve, and means responsive toaccumulation of a predetermined quantity of liquid above said valve foractuating said valve to open position. i r

3. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to said rotor during rotation thereof, a

sition for discontinuing feed of liquid to said rotor.

4. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to said rotor during rotation thereof, aframe surrounding the bottom portion of said rotor and provided with adischarge outlet for liquid drained from the rotor, a valve associatedwith said outlet and controlling discharge of liquid therefrom, meansassociated with said valve for holding it normally in closed positionduring discharge of liquid until said liquid reaches a predetermineddepth above said valve. means responsive to accumulation of apredetermined quantity of liquid above said valve for actuating saidvalve to open position, and means controlled by actuation of said valveto open po sition for interrupting the driving of said rotor.

5. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to said rotor during rotation thereof, aframe surrounding the pump portion of said rotor and provided with adischarge outlet for liquid drained from the rotor, a disc normallycontacting said drainage outlet to seal said frame from entry of vaporsor discharge of liquid, means associated with said disc for normallyholding it in closed position against said outlet during discharge ofliquid until said liquid reaches a predetermined depth above said disc,and means responsive to accumulation of a predetermined quantity ofliquid-above said disc for actuating said disc to open position.

6. In a centrifugal separator, the combination comprising, a centrifugalrotor, means for feeding liquid to said rotor during rotation thereof, aframe surrounding the pump portion of said rotor and provided with adischarge outlet for liquid drained from-the rotor, a disc normallycontacting said drainage outlet to seal said frame from entry of vaporsor discharge of liquid, a counter-weight associated with said disc fornormally holding it in closed position against said outlet duringdischarge of liquid until said liquid reaches a predetermined depthabove said disc. and means responsive to accumulation of a predeterminedquantity of liquid above said disc for actuating said disc to openposition.

WILMER HIESTAND BATH.

